F1ach: Guilds, well I played a month or so, solo, joined a guild to take my game further, for healing at raids, 2-3 weeks later I was still playing solo, the game is old and guild members are either bored and don't log in too much any more, or are to high level to bother teaming, or running alts very quickly through quests, so you get no real atmosphere cos they race through the content with you.
Fenixp: I'm mostly aiming at soloing, because... Pff, people :-P
If that's what you like to do, that's cool.
They have a skill system where (afaik) initially you can get the skills you need up to 10, to get your skills higher, you have to do Raids to get gear commensurate with your higher skill level. But, you can get yours akills up to 10 on the first island, the problem is getting gear commensurate with that 10 cos outside of raids the gear is pretty crap, you can go to the AH, but afaik the best is raid only.
The raids are good, but you will be in PUG's (if you are only soloing), so you will be raiding with noobs and the clusterfucks that entails, or with seasoned pros that will rush through the instances killing the atmosphere.
I played it for a couple of months and definitely got my moneys worth (even subbed for one month, cos I thought I would stay on). Hope you enjoy it though, its a very unique game :)